import java.util.Scanner;

/**
 * Created with IntelliJ IDEA
 * Description
 * User:华为
 * Date:2024/11/11
 * Time:15:19
 */
public class text {
    public static String func(String str){
        int[] arr = new int[200];
        StringBuilder stringBuilder = new StringBuilder();
        for (int i = 0; i < str.length(); i++) {
            char ch = str.charAt(i);
            if(arr[ch] == 0){
                stringBuilder.append(ch);
                arr[ch] = 1;
            }
        }
        return stringBuilder.toString();
    }
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while(scanner.hasNextLine()){
            String str = scanner.nextLine();
            String str1 = func(str);
            System.out.println(str1);

        }
    }
}
